Behavior study says size matters when it comes to male finger lengths

A new study finds men with short index fingers are nicer to women.

Researchers at McGill University in Canada studied finger sizes in men. The results show a link in how men behave towards women to their finger size.

The study found men whose index finger is smaller than their ring finger are more likely to smile, laugh, compromise or compliment women. On the other hand, those with larger index fingers than their ring finger exhibited a more contentious nature.

Men's index fingers are generally shorter than their ring fingers. The difference is less pronounced in women. Previous research has found that digit ratio - defined as the second digit length divided by the fourth digit length - is an indication of the amount of male hormones someone has been exposed to as a fetus. The smaller the ratio, the more male hormones.

"It is fascinating to see that moderate variations of hormones before birth can actually influence adult behavior in a selective way," said Simon Young, a McGill emeritus professor in psychiatry and co-author of the study.

A previous study found men with smaller digit ratios have more children. For women, digit ratio variation did not seem to predict how they behaved.

The study was published in the journal 'Personality and Individual Differences.'

Click here to read the full study.